Riboflavin inhibits browning of fresh-cut apples by repressing phenolic metabolism and enhancing antioxidant system

Abstract

Fresh-cut browning is a significant global challenge for fresh-cut produce. Riboflavin has been studied in terms of physiological function; however, its effect on fresh-cut browning remains elusive. Here, the changes in quality attributes including browning, phenolic metabolism, and oxidative metabolism were compared between fresh-cut apples treated with riboflavin coupled with LED-blue illumination, and control. LED-based riboflavin treatment is an effective strategy for quality preservation of fresh-cut apples, as indicated by controlled browning, microbial growth, weight loss and softening, as well as improved whiteness and soluble solid content. Enzymatic activities of polyphenol oxidase and peroxidase were repressed by the riboflavin application, whereas the phenolic content was enhanced. The reduced membrane peroxidation can be explained by the impairment of H2O2 accumulation due to an enhanced antioxidant system. In conclusion, photosensitizing riboflavin can reduce the browning of fresh-cut apples by inhibiting phenolic metabolism and strengthening the antioxidant system to avoid membrane peroxidation.